Yarn-tensioning means for spiral winding machines

ABSTRACT

Mechanism for controlling the rotational letoff speed of a yarn supply bobbin to maintain substantially constant tension of the yarn used in fabricating machines such as spiral winders and the like. The tension-controlling means includes reader means for reading the diameter of the yarn supply which acts through resilient means between the reader means and brake means to control the rotation speed of the yarn supply in accordance with the diameter of the yarn supply.

United States Patent Robert H. Knufmann Temple;

John L. Wily, Reading, both 0!, Pa. 84l,4l1

July 14, I969 July 13, I971 North American Rockwell CorporationPittsburgh, Pa.

Inventors Appl No. Filed Patented Assignee YARN-TENSIONING MEANS FORSPIRAL wmnmc MACHINES 6 Claims, 8 Drawing Figs.

us. Cl 242/1562, 242/l 29,3 rm. Cl H B65h 5913s mu ofSearch 242M298,

[56] References Cited UNITED STATES PATENTS 2,592,595 4/1952 Patterson242/! 56.2 2,988,299 6/196l Macdonaldm 242/l 56.2 3,l l7,742 1/1964Trombetta 242/1562 Primary Examiner-Leonard D. Christian Attorneys-JohnR. Bronaugh, E. Dennis OConnor and Floyd S. Levison ABSTRACT: Mechanismfor controlling the rotational letofl' speed of a yarn supply bobbin tomaintain substantially constant tension of the yarn used in fabricatingmachines such as spiral winders and the like. The tension-controllingmeans includes reader means for reading the diameter of the yarn supplywhich acts through resilient means between the reader means and brakemeans to control the rotation speed of the yarn supply in accordancewith the diameter of the yarn supply.

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mimen .u 1 m ME! 2 BF 3 L-mmw PATENTED JUL 1 3 09?! SHEET 3 OF 3 w w w,QK M fi i rixltilv$ w W J 5 m 3% w 7//////////////////////////A/////%////4///////////#//4/ 4. vim. ill 3; m mj t F k i K x YARN-TENSIONING MEANS FOR SPIRAL WINDING MACHINESBACKGROUND OF THE INVENTION Heretofore, in yarn-fabricating machines inwhich the yarn supply was rotated by the yarn as it was withdrawn fromthe supply and fabricated by the machine tension was applied to the yarnby applying a braking force on the yarn supply bobbin. The braking forceapplied to the bobbin was usually constant but since the leverageexerted by the yarn to turn the bobbin varied as the supply of yarn wasdepleted, the tension in the yarn also varied.

In efforts to provide a more uniform tension in yarn when the yarn wasused to rotate the yarn supply as it was withdrawn therefrom byfabricating means mechanism was provided to control the rotation of theyarn supply such as that shown in Us. Pats. Nos. 2,395,807 and2,397,663. As shown in these patents the means for controlling the yarntension, which means were associated with the warp beams ofwarp-knitting machines, included a pair of brakeshoes acting on thebeam, a spring or springs connected between the brakeshoes, a feelermember which was biased into engagement with the windings of the yarn onthe beam by a spring and connections between the feeler member andbrakeshoes for varying the force applied by the spring connecting thebrakeshoes to vary their braking force on the beam in accordance withthe diameter of yarn supply on the beam. While this mechanism wasdesigned to control the yarn tension by controlling the rotation of theyarn beam in accordance with the diameter of the yarn on the beam themechanism was both cumbersome and expensive. Furthermore. the number ofsprings required made it difficult to control the rotational speed ofthe beam and the tension in the yarn with the degree of accuracyrequired.

The instant invention has for its principle object the provision ofmeans for controlling the tension in yarn or a strand of materialwithdrawn from a strand supply rotatable by the strand and used in afabricating machine such as a spiral winder or the like, thetension-controlling means including spring-controlled means for applyingbraking force to the strand supply, and means for reading the diameterof the strand in the supply, said last-named means being adapted to varythe force of spring-controlled means and the force applied thereby tothe strand supply in a manner to maintain a substantially uniformtension in the strand as the strand in the supply is reduced from fullto depleted condition.

SUMMARY OF THE INVENTION Briefly summarized the invention resides in theprovision of means for controlling the tension in yarn or a strandwithdrawn from a rotatable supply as it is used in a fabricating machinesuch as a spiral winder and the like, the tension-controlling meansincluding a reader means for reading the diameter of the supply, a brakelever acting on the yarn supply to resist rotation thereof and a springbetween the reader means and brake lever. The force of the spring isgradually reduced to reduce the braking force of the brake lever on theyarn supply by the reader means as the diameter of the yarn or strand inthe supply is reduced between full and depleted limits.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of onedeck of a machine for spirally winding yarn on a core with strand supplyand tensioning fixtures according to the invention incorporated therein;

FIG. 2 is a view ofthe machine as seen from the left of FIG.

FIG. 3 is an elevational view on an enlarged scale of one of the yarnsupply fixtures shown in FIG. I;

FIG. 4 is a partial plan view of FIG. 3;

FIG. 5 is a view partly in plan and partly in cross section takensubstantially on the line and in the direction of the arrnum nf FIG 3'FIG. 6 is a cross-sectional view taken on the line and in the directionof the arrows 6-6 of FIG. 4;

FIG. 7 is a cross-sectional view taken on the line and in the directionof the arrows 7-7 of FIG. 4; and

FIG. 8 is a detail view of a portion of the mechanism of FIG. 3.

Referring to FIGS. 1 and 2 of the drawings there is shown one of thewinding decks or heads I0 ofa machine for forming reinforced hose andthe like including a base member ll, vertical plates I2 and supported onthe base member and forming a fixed portion of the deck in which theoperating means is carried for a rotary member 16. The rotary member 16carries a plurality of like fixtures 17 each of which is adapted tosupply and tension a yarn 20 directed to a collector or guide ring 2]where the yarn is spirally wound on a core or mandrel 22 moving axiallythrough the guide ring. Except for the fixtures I7 the construction andoperation of the head 10 is conventional and forms no part of theinstant invention.

The fixtures I7 each include a base 25 having a bushing 26 (see FIGS. 3and 6), the base being secured to the rotary member 16 between anenlarged head 27 at one end of the bushing and a nut 30 threadablycarried on the other end of the bushing for engagement with theunderside of the rotary member. Secured in a bore 3] in the bushing 26as by pin 32 is one end 35 ofa shaft or spindle 36. The spindle 36 has abearing portion 37 for mounting the inner race ofa ball bearing 40.Mounted on the outer race of the bearing 40 is an enlarged lower annularportion 42 of a sleeve 45. The upper end of the sleeve 45 is bored toreceive the outer race of a ball bearing 46. The inner race of the ballbearing 46 is mounted on a reduced upper end portion 47 of the spindle36 between a shoulder 50 on the spindle and a C-ring 51 carried in agroove in the portion 47. The sleeve 45 is retained against axialmovement on the outer races of bearings 40 and 46 by shoulders 52 and55, respectively, formed in the sleeve. The sleeve 45 which is adaptedto receive the yarn bobbin 56 is provided with raised spirally extendingribs 57 (FIGS. 5, 6 and 8) for engagement with the inner bore of thebobbin to prevent relative rotation between the bobbin and sleeve.

Rotation of the bobbin 56 on the spindle 36 of the fixture 17 iscontrolled to apply tension on the yarn 20 as it is withdrawn from thebobbin and wound on the core 22. For this purpose the outer periphery ofportion 42 of the spindle is adapted to be engaged by a brakcshoe 60(see FIGS. 3 and 5 of leather or the like, secured by adhesive to abrake lever l pivotally mounted on a stud 62 carried in the base 25 formovement in a plane parallel to the plane of the base. An arm 65 of thebrake lever M is connected by a coil-type tension spring 66 to a nut 67forming a part ofa reader means 68 for reading the diameter of the yarnsupply on the bobbin S6. The nut 67 is carried on a threaded spindle 70mounted for rotation in cars 71 projecting from one arm 72 ofa lever 75pivoted on a stud 76 carried in a portion 77 of the base 25 (FIGS. 3, 4and 5). Thumb nuts 80 are provided on opposite ends of the spindle 70 bymeans of which the spindle may be rotated to manually adjust theposition of the nut 67 thereon in preparation for operation to vary thetension in spring 66 and the braking force applied by the brake lever Mto the sleeve 45 as may be required by the particular yarn employed orother conditions present.

The lever 75 is provided with a second arm 81 having an open-ended slot82 for receiving one arm 85 of a lever 86 pivotally mounted on a pin 87carried in the portion 77 of the base 25 (FIGS. 3 and 7). The lever 86has a second arm 90 with an arcuate feeler surface 9] adapted to readthe outer diameter of the yarn windings on the bobbin 56 through aflexible strip 92, of plastic material such as Teflon or the like,secured by screws to a post 96 carried in the base 25 (FIGS. 3, 4 and7). The spring 66 connected between the arm 65 of the brake lever 61 andthe nut 67 on the lever 75 tends to turn the lever clockwise about thestud 76 and to turn the lever 86 counterclockwise, as viewed in FIG. 7to maintain the surface 91 of arm 90 in engagement with strip 92, andthe latter in engagement with the yarn on the bobbin, and to turn thebrake lever counterclockwise as viewed in FIG. 5, to maintain thebrakeshoe 60 in braking engagement with the portion 42 of the sleeve 45.

As will be understood, in the absence of a braking mechanism as providedby the instant invention, when the bobbin has a full supply of yarn thepull on the yarn to turn the bobbin would be at its minimum and as thediameter of the supply decreases the required pull would correspondinglyincreasev The relationship between the brake lever 61 and the levcrs 75and 86 of the reader means 68 is such that when the bobbin 45 has a lullsupply of yarn the braking force exerted by the reader means through thespring 66 and the brake lever 6| on the sleeve 45 is at its maximum toprovide the required tension in the yarn at the fabricating point.Thereafter as the diameter of the windings of yarn is gradually reducedthe levers 75 and 86 of the reader means 68 are moved to graduallyreduce the braking force applied through the spring 66 and brake leveron the sleeve to thereby maintain a substantially uniform tension in theyarn between the full and depleted limits of the yarn supplyv It will beunderstood that the improvement specifically shown and described bywhich the above results are obtained can be changed and modified invarious ways without departing from the invention herein disclosed.

We claim:

1. In a machine for spirally winding a strand onto a core member, saidmachine having rotatable means for supporting a wound supply from whichsaid strand is withdrawn as it is wound onto said core, and means forcontrolling the tension in said strand withdrawn from said supplyincluding a brake lever for applying brake force to said rotatablesupporting means, reader means for engaging and reading the diameter ofthe supply of said strand, and resilient means interconnecting saidbrake lever and said reader means to bias said brake lever in a brakingcondition with said rotatable supporting means and said reader means inreading engagement with the supply of said strand, said reader meansacting through said resilient means to vary the braking force applied tosaid rotatable sup porting means by said brake lever in accordance withthe diameter of the supply of said strand.

2 A machine according to claim 1 in which said resilient means comprisesa spring.

3. A machine according to claim I in which reader means includes a firstlever for engaging said supply of said strand, and a second levermovable by said first lever in accordance with the diameter of saidsupply of said strand, and said resilient means interconnects said brakelever and said second lever of said reader means.

4. in a machine for spirally winding yarn onto a core member, saidmachine having rotatable means for supporting a supply from which saidyarn is withdrawn as it is wound onto said core, and means forcontrolling the tension in said yarn withdrawn from said supplyincluding a brake lever for engaging said rotatable supporting means,reader means for engaging and reading the diameter of the supply ofyarn, and resilient means interconnecting said brake lever and saidreader means to maintain said brake lever in engagement with saidrotatable supporting means and said reader means in reading engagementwith said supply of yarn, said reader means acting through saidresilient means to vary the braking force applied to said rotatablesupporting means by said brake lever in accordance with the diameter ofsaid supply of yarn, said reader means includes a first lever forengaging said supply of yarn, and a second lever movable by said firstlever in accordance with the diameter of said supply of yarn and saidresilient means comprises a spring, said spring interconnecting saidbrake lever and said second lever of said reader means, furthercomprising means on said second lever of said reader means for adjustingthe force of said spring interconnecting said brake lever and saidsecond lever of said reader means.

5. A machine according to claim 4 in which said adjusting means for saidspring on said second lever of said reader means includes a member onsaid second lever for engaging one end of satd spring and there IS meansfor ad usting the position of said member on said second lever.

6. A machine according to claim 5 in which said means for adjusting theposition of said member on said second lever comprises a threadedspindle on which said member is mounted, said threaded spindle beingrotatably mounted on said second lever to adjust the position of saidmember on said second lever.

1. In a machine for spirally winding a strand onto a core member, saidmachine having rotatable means for supporting a wound supply from whichsaid strand is withdrawn as it is wound onto said core, and means forcontrolling the tension in said strand withdrawn from said supplyincluding a brake lever for applying brake force to said rotatablesupporting means, reader means for engaging and reading the diameter ofthe supply of said strand, and resilient means interconnecting saidbrake lever and said reader means to bias said brake lever in a brakingcondition with said rotatable supporting means and said reader means inreading engagement with the supply of said strand, said reader meansacting through said resilient means to vary the braking force applied tosaid rotatable supporting means by said brake lever in accordance withthe diameter of the supply of said strand.
 2. A machine according toclaim 1 in which said resilient means comprises a spring.
 3. A machineaccording to claim 1 in which reader means includes a first lever forengaging said supply of said strand, and a second lever movable by saidfirst lever in accordance with the diameter of said supply of saidstrand, and said resilient means interconnects said brake lever and saidsecond lever of said reader means.
 4. In a machine for spirally windingyarn onto a core member, said machine having rotatable means forsupporting a supply from wHich said yarn is withdrawn as it is woundonto said core, and means for controlling the tension in said yarnwithdrawn from said supply including a brake lever for engaging saidrotatable supporting means, reader means for engaging and reading thediameter of the supply of yarn, and resilient means interconnecting saidbrake lever and said reader means to maintain said brake lever inengagement with said rotatable supporting means and said reader means inreading engagement with said supply of yarn, said reader means actingthrough said resilient means to vary the braking force applied to saidrotatable supporting means by said brake lever in accordance with thediameter of said supply of yarn, said reader means includes a firstlever for engaging said supply of yarn, and a second lever movable bysaid first lever in accordance with the diameter of said supply of yarnand said resilient means comprises a spring, said spring interconnectingsaid brake lever and said second lever of said reader means, furthercomprising means on said second lever of said reader means for adjustingthe force of said spring interconnecting said brake lever and saidsecond lever of said reader means.
 5. A machine according to claim 4 inwhich said adjusting means for said spring on said second lever of saidreader means includes a member on said second lever for engaging one endof said spring and there is means for adjusting the position of saidmember on said second lever.
 6. A machine according to claim 5 in whichsaid means for adjusting the position of said member on said secondlever comprises a threaded spindle on which said member is mounted, saidthreaded spindle being rotatably mounted on said second lever to adjustthe position of said member on said second lever.